流动注射在线萃取—火焰原子吸收光谱法测定人发中微量镉和铅

本文建立了一个流动注射在线萃取－火焰原子吸收测定人发中微量镉和铅的方法，对含Ｃｄ和Ｐｂ分别为０．０２μｇ／ｍｌ和０．２０μｇ／ｍｌ的溶液，其相对标准偏差分别为３．４％和３．８％（ｎ＝９），Ｃｄ和Ｐｂ的灵敏度分别提高２１倍和２３倍，分析速度达３６次／ｈ，Ｃｄ和Ｐｂ的回收率分别在８７．３％－９７．０％和９１．９％－１０７．３％之间，文中还详细研究了各种实验参数的选择，测定人发样的结果与文献值相符。     

烟道喷射石灰(石)烟气脱硫技术综述

本文介绍了近几年发展起来的一种简单、中效、适合燃烧中低硫煤的工业锅炉的烟气脱硫技术———烟道喷射石灰 (石 )烟气脱硫技术。从湿法、干法、半干法 3种工艺对烟道喷射烟气脱硫进行了介绍 ,并提出新型脱硫吸收剂是提高烟道脱硫效率的可行方法。最后指出烟道脱硫今后的研究方向     

Hydraulic characterization for steam enhanced remediation conducted in fractured rock

To explore the viability of Steam Enhanced Remediation (SER) in fractured rock a small-scale steam injection and water/vapour extraction pilot study was conducted at the former Loring Air Force Base in northern Maine, USA. A detailed well testing program was undertaken to assist in the design of the injection and extraction well array, and to assess the possibility of off-site heat and contaminant migration. A structurally complex limestone having low matrix porosity and a sparse distribution of fractures underlies the study site. To characterize the groundwater and steam flow pathways, single-well slug tests and more than 100 pulse interference tests were conducted. The results of the well testing indicate that the study site is dominated by steeply dipping bedding plane fractures that are interconnected only between some wells in the injection/extraction array. The SER system was designed to take advantage of interconnected fractures located at depth in the eastern end of the site. An array of 29 wells located in an area of 60 by 40 m was used for steam injection and water/vapour extraction. The migration of heat was monitored in several wells using thermistor arrays having a 1.5 m vertical spacing. Temperature measurements obtained during and after the 3 month steam injection period showed that heat migration generally occurred along those fracture features identified by the pulse interference testing. Based on these results, it is concluded that the pulse interference tests were valuable in assisting with the design of the injection/extraction well geometry and in predicting the migration pathways of the hot water associated with the steam injection. The pulse interference test method should also prove useful in support of any other remedial method dependant on the fracture network for delivery of remedial fluid or extraction of contaminants.     

Effect of mixing chamber venturi,injection timing,compression ratio and EGR on the performance of dual-fuel engine operated with HOME and CNG

Stringent environmental policies and the ever increasing demand for energy have triggered interest in novel combustion technologies that use alternative fuels as energy sources. Of these, pilot-ignited compressed natural gas (CNG) engines that employ small biodiesel pilot to ignite a premixed natural gas–air mixture have received considerable attention. This paper discusses the effect of mixing chamber venturi, injection timing, compression ratio and exhaust gas recirculation (EGR) on the performance of dual-fuel engine operated on biodiesel derived from honge oil and is called honge oil methyl ester (HOME) and CNG. The proposed study mainly focuses on the manifold induction of CNG along with HOME injection. However, CNG can also be injected using port or direct gas injector (Lakshmanan and Nagarajan 2010, Energy 35, pp. 3172–3178). The future study will involve these methods of CNG injection. From this study, it is concluded that an advanced injection timing and an increased compression ratio resulted in increased brake thermal efficiency and reduced smoke, hydrocarbons and carbon monoxide emissions. However, nitrogen oxides (NO _x ) emission increased significantly. The increased NO _x emission was effectively reduced with EGR method. A mixing chamber venturi of 3 mm size, injection timing of 27° before top dead centre (BTDC), compression ratio of 17.5 and 10% EGR were found to be optimum for the modified compression ignition engine that was operated on CNG–HOME dual-fuel mode.     

聚天冬氨酸作为油田阻垢剂的研究进展

目前国内油田注水管线清洗需要性能更佳的阻垢剂。经过对比研究,选择聚天冬氨酸作为油田阻垢清洗剂。同传统的阻垢剂相比,它的阻垢效果好,而且生物降解性极佳。分析了合成条件、相对分子量对合成的聚天冬氨酸阻垢性能的影响,确定了最佳的合成条件,并提出了聚天冬氨酸在其他领域的应用和今后的发展方向。     

AN EFFICIENT METHOD OF APPLYING ALUMINUM SALTS FOR SEDIMENT PHOSPHORUS INACTIVATION IN LAKES1

ABSTRACT: Alum and sodium aluminate were injected into the hypolimnion of eutrophic Kezar Lake, New Hampshire, with a specially designed applicator mechanism. This new method of applying aluminum salts to achieve phosphorus inactivation included two separate chemical distribution systems mounted on a hydraulic weed harvester. The design of the applicator system is described, and its cost-effectiveness is compared with other aluminum salt injections.     

惰性气体抑制瓦斯爆燃火焰传播特性实验研究*

为研究惰性气体抑制瓦斯爆燃火焰传播特性,在自行搭建的中尺度爆炸激波管道上,采用数据采集系统、压电式传感器、火焰传感器、同步控制系统和激光纹影测试系统,通过对比4种不同喷射压力（0.5,1.5,2.5,3.5 MPa）的实验工况,选用N2做为惰性介质时抑制火焰的传播特性与喷射压力密切相关,火焰传播速度随着喷射压力增加呈现先增加后减弱的趋势。研究结果表明:少量N2在管道中扩散,加剧了未反应预混气体的扰动状态,造成火焰阵面褶皱的卷吸能力增强,进而加速化学反应进程,促进预混气体燃烧;喷射压力为1.5 MPa时,火焰阵面拉升、变形最强,火焰传播速度提高,最高可达到250 m/s;喷射压力为3.5 MPa时,火焰阵面出现明显三维凹陷结构,运动发生明显滞后现象,火焰传播速度大幅度降低至5.4 m/s,惰性气体抑制火焰传播效果明显。     

基于CFD的注采管柱接头修复胶液渗流规律研究

为探讨注胶方法修复井下注采管柱螺纹接头缝隙的可行性,采用计算流体动力学欧拉-欧拉多相流方法构建胶液在注采管柱接头缝隙内的渗流流动数值仿真模型,模拟注胶压力驱动下修复胶液在管柱接头螺纹缝隙内的渗流过程,通过多工况条件下胶液在螺纹缝隙内的渗流数值模拟,研究注胶压力、胶液密度和螺纹失效缝隙对胶液渗流过程的影响.结果表明:基于...     

基于正压密封方法的闭式采空区灭火技术

为提高闭式采空区密闭漏风控制效果,基于矿井空气流动基础理论,运用RFPA软件建立了注氮气室正压密封采空区数值模型,模拟分析了注氮气室正压作用对采空区密闭漏风行为的影响规律,提出了基于注氮气室正压密封方法的采空区灭火技术,并在恒大煤矿5333工作面采空区进行了应用.结果表明,在气室内氮气相对正压作用下,通风巷道向采空区漏风速度快速减小至0,并最终产生反向,形成由气室向外部微量漏氮气的状态,5333采空区采取正压密封方法后,内部CO、C2H4和温度快速消失和降低至安全范围值.     

Frontier science and challenges on offshore carbon storage

● The main direct seal up carbon options and challenges are reviewed. ● Ocean-based CO₂ replacement for CH₄/oil exploitation is presented. ● Scale-advantage of offshore CCS hub is discussed. Carbon capture and storage (CCS) technology is an imperative, strategic, and constitutive method to considerably reduce anthropogenic CO₂ emissions and alleviate climate change issues. The ocean is the largest active carbon bank and an essential energy source on the Earth’s surface. Compared to oceanic nature-based carbon dioxide removal (CDR), carbon capture from point sources with ocean storage is more appropriate for solving short-term climate change problems. This review focuses on the recent state-of-the-art developments in offshore carbon storage. It first discusses the current status and development prospects of CCS, associated with the challenges and uncertainties of oceanic nature-based CDR. The second section outlines the mechanisms, sites, advantages, and ecologic hazards of direct offshore CO₂ injection. The third section emphasizes the mechanisms, schemes, influencing factors, and recovery efficiency of ocean-based CO₂-CH₄ replacement and CO₂-enhanced oil recovery are reviewed. In addition, this review discusses the economic aspects of offshore CCS and the preponderance of offshore CCS hubs. Finally, the upsides, limitations, and prospects for further investigation of offshore CO₂ storage are presented.